• Title/Summary/Keyword: Reinforcement methods

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Case study on the external prestressing method strengthened carbon fiber reinforced plates. (탄소섬유 보강판 전용 정착장치를 이용한 외부 프리스트레싱 보강공법 사례연구)

  • 정원용;임공묵
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.1003-1006
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    • 2003
  • In recent years, FRP plates have been studied for flexural reinforcement of RC structures due to easy installation and good Quality control. This study presents experimental field test results for the effectiveness of flexural reinforcement of the RC slab using external prestressing with thin CFRP strips made by the pultrusion process. It was demonstrated that flexural strength was considerably increased with relatively easy installation when compared to the other methods used for the composite reinforcement.

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Reinforcement Performance Evaluation Experiment Research of RC Structure Which High Strength Clear Glass Fiber Panel was Used (고강도 투명 유리섬유 패널을 이용한 RC구조물의 보강 성능평가 실험 연구)

  • Kang, In-Seok;Lee, Han-Seung;Lee, Ok-Sin
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.121-124
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    • 2005
  • The existing reinforcement methods of construction are the actual condition without the method of checking exact injection of adhesives clearly by the opacity of reinforcement material. In this study, in order to solve such a problem, the high strength transparent panel using a glass fiber is developed and in order to examine reinforcement effect of a panel clearly, the structure performance evaluation experiment was conducted. As a result, we knew that it can check with the naked eye the injection process of adhesives and reinforcement effect was also observable.

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The comparison between experimental and FEA results for crack initiation due to corrosion of reinforcement (콘크리트 구조물의 철근부식으로 인한 균열발생에 관한 실험적, 해석적 결과의 비교)

  • 장상엽;김용철;조용범
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.693-698
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    • 2003
  • Corrosion of reinforcement and deterioration of concrete short the lifetime of reinforced concrete structure and affect the safety of the structure. In particular, the corrosion of reinforcement causing the inner pressure of the interface between the concrete and reinforcement is known to significantly contribute to the premature deterioration of concrete structure. Several attempts have been made to predict the cracking time of the concrete structure. However, problems such as the lack of reproducibility of concrete tests and non-uniformity of materials have hampered thess kinds of studies. Thus, the mechanism of the concrete cracking due to reinforcement corrosion is in the way. This studymeasured the mechanical properties of corrosion products using the nano-indentation test method. Likewise, the critical thickness of corrosion products for the cracking of concrete cover was investigated using the finite element and experimental methods.

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Performance Improvement of Genetic Algorithms by Reinforcement Learning (강화학습을 통한 유전자 알고리즘의 성능개선)

  • 이상환;전효병;심귀보
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.03a
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    • pp.81-84
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    • 1998
  • Genetic Algorithms (GAs) are stochastic algorithms whose search methods model some natural phenomena. The procedure of GAs may be divided into two sub-procedures : Operation and Selection. Chromosomes can produce new offspring by means of operation, and the fitter chromosomes can produce more offspring than the less fit ones by means of selection. However, operation which is executed randomly and has some limits to its execution can not guarantee to produce fitter chromosomes. Thus, we propose a method which gives a directional information to the genetic operator by reinforcement learning. It can be achived by using neural networks to apply reinforcement learning to the genetic operator. We use the amount of fitness change which can be considered as reinforcement signal to calcualte the error terms for the output units. Then the weights are updated using backpropagtion algorithm. The performance improvement of GAs using reinforcement learning can be measured by applying the pr posed method to GA-hard problem.

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A Function Approximation Method for Q-learning of Reinforcement Learning (강화학습의 Q-learning을 위한 함수근사 방법)

  • 이영아;정태충
    • Journal of KIISE:Software and Applications
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    • v.31 no.11
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    • pp.1431-1438
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    • 2004
  • Reinforcement learning learns policies for accomplishing a task's goal by experience through interaction between agent and environment. Q-learning, basis algorithm of reinforcement learning, has the problem of curse of dimensionality and slow learning speed in the incipient stage of learning. In order to solve the problems of Q-learning, new function approximation methods suitable for reinforcement learning should be studied. In this paper, to improve these problems, we suggest Fuzzy Q-Map algorithm that is based on online fuzzy clustering. Fuzzy Q-Map is a function approximation method suitable to reinforcement learning that can do on-line teaming and express uncertainty of environment. We made an experiment on the mountain car problem with fuzzy Q-Map, and its results show that learning speed is accelerated in the incipient stage of learning.

Development of the Fuzzy Expert System for the Reinforcement of Tunels during Construction (터널 시공 중 보강공법 선전용 퍼지 전문가 시스템 개발)

  • 김창용;박치현;배규진;홍성완;오명렬
    • Journal of the Korean Geotechnical Society
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    • v.16 no.6
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    • pp.127-139
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    • 2000
  • In the study, an expert system was developed to predict the safety of tunnel and select proper tunnel reinforcement system using fuzzy quantification theory and fuzzy inference rule based on tunnel information database, For this development, many tunnelling sites were investigated and the applied countermeasures were studied after building tunnel database. There will be benefit for the deciding tunnel reinforcement method in the case of poor ground condition. The expert system developed in the study has two main parts, pre-module and post-module. Pre-module is used to decide input items of tunnel information based on the tunnel face mapping information which can be easily obtained in in-situ site. Then, using fuzzy quantification theory II, fuzzy membership function is composed and tunnel safety level is inferred through this membership function. Post-module is used to infer the applicability of each reinforcement methods according to the face level. The result of the predicted reinforcement system level was similar to measured ones. In-situ data were obtained in three tunnel sites including subway tunnel under Han River. Therefore, this system will be helpful to make the mose of in-situ data available and suggest proper applicability of tunnel reinforcement system to development more resonable tunnel support method without dependance of some experienced experts opinions.

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Effects of Three-Week Contract-Relax Interventions with and without Reinforcement Using Temporal Summation for Flexibility and Balance Ability in Young People with Hamstring Shortening (공간적 가중을 이용한 강화 유무에 따른 3주간 수축-이완 중재가 넙다리뒤근 단축 대상자의 유연성과 균형능력에 미치는 효과)

  • Kim, Yong-Hun;Park, Du-Jin
    • PNF and Movement
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    • v.20 no.3
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    • pp.383-390
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    • 2022
  • Purpose: The purpose of this study was to examine the effect of three-week contract-and-relax (CR) interventions with and without reinforcement using temporal summation for flexibility and dynamic balance ability in young people with hamstring shortening. Methods: This study was conducted on 20 female college students with hamstring shortening. The participants were divided equally into two groups using stratified randomization: the CR group (CRG) and the CR with reinforcement group (CRRG). All interventions were applied three times a week for three weeks. The passive straight leg raise (PSLR) test and functional reaching test (FRT) were conducted on each participant before and after the three-week intervention. Results: In both groups, PSLR and FRT improved significantly after the three-week intervention compared to before intervention (p < 0.01). The amount of change in PSLR after the three-week intervention was significantly higher in CRRG than in CRG (p < 0.05). Conclusion: Three-week CR interventions with and without reinforcement were effective in improving PSLR and FRT. To improve hamstring shortening, CR intervention with reinforcement may be more useful than CR intervention without reinforcement.

A Study for the Performance Based Strengthening Design of Underground Box Structure in Urban Railway (도시철도 지하박스 구조물의 내진성능 보강설계 연구)

  • Kwon, Min-Ho;Kim, Si-Kyeok;Kim, Ki-Hong;Jang, Young-Du;Kim, Jin-Ho
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.1143-1148
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    • 2011
  • In this study, seismic structural reinforcement are carried out, based on the estimated seismic performance of underground box structures in urban railway, and displacement based design method was developed to enhance seismic performance of structures. New seismic reinforcement design method is proposed and compared with existing design methods. And presented an overview of the developed design methodology through a design example to verify the validity of that methods.

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A Study on the Meaning of Theory that Acupuncture has no Reinforcement -Focusing on the method of reinforcement and reduction in Huangdineijing- (침무보법(鍼無補法)의 의미에 대한 고찰(考察) -『황제내경(黃帝內經)』의 보사법(補瀉法)을 중심으로-)

  • Yun, Ki-ryoung;Baik, Yousang;Jang, Woo-chang;Jeong, Chang-hyun
    • Journal of Korean Medical classics
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    • v.31 no.2
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    • pp.141-153
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    • 2018
  • Objectives : Acupuncture therapy's reinforcement and reduction method is now widely used in the clinical practices. Meanwhile, there has been a voice of concern since the past that acupuncture has no reinforcement. This thought has not been given enough discussion, and the paper attempts to remedy this absence and verify the validity of the concern. Methods : The acupunctural reinforcement and reduction method found in the Huangdineijing is reviewed, and a number of medical books that discuss the idea of lack of reinforcement in acupuncture are studied. Results : Huangdineijing describes the acupunctural unique feature of reduction. The text explains that acupuncture work in a way that is different that medicine, and thus cannot be used for a disease based on deficiency. In addition, it warned the loss of the primordial qi when needling oneself. Reinforcement in the reinforcement and reduction technique as described in Huangdineijing mainly revolves around preventing the loss of the primordial qi. Conclusions : The purpose of the acupunctural reinforcement and reduction is to control the body's disproportional qi deficiency and excess, where some parts of the body has more qi than others. The reinforcement in "acupunctural reinforcement and reduction method" and the reinforcement in "acupuncture only has reduction and no reinforcement" within the thought of "acupuncture has no reinforcement" are different in that one deals with controlling the imbalance of qi in body, and the other deals with dispelling the deficiency by flowing the qi in the viewpoint of entering and out. This calls for a need to establish the proper acupunctural points, numbers, and times for each disease based on the theory of "acupuncture has no reinforcemen."

Parametric Study on the Lateral Resistance of Offshore Piles with Enlarged Upper Section (상부단면 확대형 해상 말뚝의 횡방향 지지 성능에 미치는 변수 연구)

  • Jang, In-Sung;Kwon, O-Soon;Jung, Young-Hoon;Youn, Hee-Jung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.1
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    • pp.1-9
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    • 2010
  • Pile reinforcement systems with enlarged upper section are newly introduced by using a mechanism that most of horizontal forces are resisted in the upper part of the pile. The new systems are expected to be effectively applicable to the marine structures including port and harbor facilities. In this study, three different reinforcement methods such as bucket pile type, top base pile type, and grouting reinforcement type were utilized in the 3-D. numerical simulations. The parametric study deals with the effects of various factors including soil types and stratigraphy, reinforcement methods, type and dimension of the pile on the lateral behaviors of the pile. The results show that the reinforcement method with bucket pile is the most efficient one compared to the top base pile type and grouting reinforcement type.